A scrupulous person is best following the moral guidance of a regular confessor. That is the classic pastoral approach to scrupulosity. Using other sources, such as this website, is not so healthy. A scrupulant needs an experienced and patient confessor and it is best if they find one Priest to make their confessions to and make these kinds of inquiries of.
Scrupulous people should also probably avoid too much of the pre-Vatican II Moral Theology handbooks (and that—those were mainly meant for Priests and Confessors and those who were theologically trained anyway (most were not meant for lay readers), and the scrupulous can easily get “in a state” and get all kinds of confused. “Did I gravely sin materially but not formally by putting myself in a possible (?) proximate occasion of sin without full knowledge that was grave matter even though I did not actually commit sin X while in that state…does that mean it is formally a venial sin even though it involves the grave matterof putting myself in a voluntary superfluous proximate occasion of sin …and I went against my conscience, so wouldn’t it be formally mortal, but my conscience is scrupulous, thus defective and aren’t I supposed to not trust the judgment of a scrupulous conscience in doubtful matters?.. and was the situation really a proximate occasion of sin in the first place? It might have been more remote. How am I going to explain this in confession? Wait, did I give scandal by being there?..and on and on”
^ A scrupulous person could be up all night trying to wrap their head around that.
It is like a hypochondriac looking at a medical textbook—they would be better off seeing a doctor in person.
The quote you have there seems to be from an article written By Fr. Farraher S.J. in 1956 and is probably meant for Priests and theologians, not lay people in the first place. It is technical and can be confusing, describing differences between the opinions of various moral theologians. Those kind of things are best avoided by the scrupulous. The scrupulous should rely on the advice of their chosen Confessor or spiritual advisor or Pastor and the moral theology articles are best left to them to interpret and apply to your questions.